Ferns are among the most interesting plants in the plant world. Varieties in Hawaii range from dainty filmy ferns less than one inch in length to stately tree ferns over 40 feet high, and inhabit areas varying from dry, barren lava flows to impenetrable rain jungles.

More primitive than flowering plants, ferns reproduce by means of small, dust-like bodies called spores. These spores are often carried in the air, and are so lightweight that they can be blown for thousands of miles by winds. The ferns of Hawaii, or their ancestors, apparently reached these islands with the help of winds, except for those introduced recently by man.